Dean, sorry man even you've been mislead, just a bit.
I have had exact species, and still have 1 small fluorescent green piece from a collecting trip to WildCoast in 2004.
I have only received similar as imports, maybe 3-4 times in 10years?
It is Palythoa.
The deeply imbedded polyps within thickened coenenchyme is a dead give away.
Coenenchyme is the common tissue shared between polyps in the group .
Overall, Zoanthid, means jack.
It covers all related, similar, dissimilar organisms.
Yes, "Zoanthus" , collectively covers the FAMILY which includes the piece pictured.
Classification of the Zoantharia:
Class Anthozoa Sub-Class Hexacorallia (Zoantharia)
Order Zoantharia (=Zoanthidea, Zoanthiniaria)
Sub-Order Brachycnemina
Family Neozoanthidae
Genus: Neozoanthus
Family Sphenopidae
Genera: Palythoa, Protopalythoa, Sphenopus
Family Zoanthidae
Genera: (Acrozoanthus), Isaurus, Zoanthus
Sub-Order Macrocnemina
Family Epizoanthidae
Genera: Epizoanthus, (Thoracactis)
Family Parazoanthidae
Genera: Savalia, Isozoanthus, Parazoanthus
"Protopalythoa" now relegated to Palythoa, I think - about 1-2y ago.
But it would be like showing Montipora spp, and saying Scleractinia, or SPS...too broad a grouping.
Kinda right, but not accurate enough for ID purposes if accurate habits/needs required.
It too is just an
example of Zoanthidae and thereafter it gets rather dim...
Acceptable "HOBBY" alternatives would be "seamat", "colonial anemones" , "false coral" even though alot aren't physically connected as a colony, NOR are they anemones.
Here's some related pix
Another to help, as bright orange is rarely seen..heheh
No direct feeding required, a healthy population of well-fed fish is enough source of nourishment. It CAN eat, zooplankton and substances meaty/protein rich particles too.
Good-medium intensity light, and a decent brisk flow round off its needs.
Why are a few polyps are damaged? Predator, pest or parasite ?
INVESTIGATE !!
The piece is a tad faded/blached as well. Follow-up with above pointers and watch it deepen colour, open a bit more frequently.
They do NOT remain open as much as related species.
Growth rate is much slower too.
Hope that fuels your enthusiasm!